Nitrazine

Nitrazine

Names
IUPAC name (3E)-3-[(2,4-Dinitrophenyl)hydrazono]-4-oxonaphthalene-2,7-disulfonic acid
Other names Nitrazine yellow; Phenaphthazine
Identifiers
CAS Registry Number	1716-22-9 Y
ChemSpider	5288340 Y
InChI InChI=1S/C16H10N4O11S2/c21-16-11-3-2-10(32(26,27)28)5-8(11)6-14(33(29,30)31)15(16)18-17-12-4-1-9(19(22)23)7-13(12)20(24)25/h1-7,17H,(H,26,27,28)(H,29,30,31)/b18-15- Y Key: IHRSXGONVFFQQF-SDXDJHTJSA-N Y InChI=1/C16H10N4O11S2/c21-16-11-3-2-10(32(26,27)28)5-8(11)6-14(33(29,30)31)15(16)18-17-12-4-1-9(19(22)23)7-13(12)20(24)25/h1-7,17H,(H,26,27,28)(H,29,30,31)/b18-15- Key: IHRSXGONVFFQQF-SDXDJHTJBN
Jmol-3D images	Image
PubChem	6911856
SMILES [O-][N+](=O)c1ccc(c([N+]([O-])=O)c1)N/N=C3/C(=C\c2c(ccc(c2)S(=O)(=O)O)C3=O)S(=O)(=O)O
Properties
Chemical formula	C16H10N4O11S2
Molar mass	498.40 g/mol
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Y verify (what is: Y/N?)
Infobox references

Nitrazine or phenaphthazine is a pH indicator dye often used in medicine. More sensitive than litmus, nitrazine indicates pH in the range of 4.5 to 7.5. Nitrazine is usually used as the disodium salt. Some uses include:

• To test vaginal pH during late pregnancy to determine the breakage of the amniotic sac.^[1] While vaginal pH is normally acidic, a pH above 7.0 can indicate that the amniotic sac has ruptured.^[2] (However, elevated pH can also be associated with bacterial vaginosis.)^[3]
• To perform a fecal pH test for diagnosing intestinal infections or other digestive problems^[4]
• In civil engineering, to determine the carbonatation spread in concrete structures and therefore assess the state of the rebar's passivation film.

References